Common video slot machines randomly select and display an array of symbols using virtual reels, then grant an award to a player based on the occurrence of certain symbol combinations across paylines. Typically, the game ends after a single spin of the reels and any award is granted. There is no particular feature in such a game that draws the player into playing longer, since the game opportunities are identical from game to game.
What is desirable, for both the player and the casino owner, is a game played on a video slot machine that effectively varies the game, from game to game, and provides added incentive for a player to keep playing. The game should also convey to the player that a large award is possible for each game. Such a gaming machine will generate increased revenue to the casino by increased play of the gaming machine.